1. Field of the Invention
The present invention generally relates to vehicle suspension systems. More specifically, the present invention relates to an improved suspension damping system to be incorporated into the suspension system of a vehicle, such as a bicycle.
2. Description of the Related Art
Suspension systems, in general, produce both a spring force and a damping force in response to relative movement of movable portions of the suspension system. Suspension damping systems generally produce a damping force that varies with the relative velocity of the movable portions of the damping assembly. A goal in suspension design is to achieve desirable levels of damping force throughout the range of commonly experienced velocities of the suspension system. Attempts to fulfill this goal have met with varying degrees of success and typically include providing multiple damping circuits, each of which are primarily effective over only a portion of the total velocity range.
However, in connection with suspension damping systems applicable to bicycle suspension systems, an overriding design constraint is the relatively small physical space that is available for housing the damping system. In addition, because a bicycle generally is human-powered, another important design constraint is weight. That is, the overall size and weight of usable or marketable bicycle suspension systems are severely restricted in comparison to other vehicles, such as automobiles, for example. Due to such constraints, prior art bicycle suspension damping systems typically provide a desirable level of damping force during only a portion of the entire range of velocity of the suspension system. For example, some prior art bicycle damping systems provide a desirable level of damping force at low velocities but not at high velocities, while other prior art damping systems provide desirable damping force at high velocities but have undesirable characteristics at low velocities. Accordingly, what is needed is an improved bicycle damping system which conforms to the prevailing physical constraints of bicycle suspension systems and also provides a desirable level of damping force throughout a greater range of expected suspension system velocities than the prior art.